A Drop Of Mercury Has A Radius Of 3.00 Mm At Room Temperature. The Surface Tension Of Mercury At That Temperature Is 0.465 Nm–1. Find Excess Pressure Inside The Drop And The Total Pressure Inside The Drop. The Atmospheric Pressure Is .

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Question

A drop of mercury has a radius of 3.00 mm at room temperature. The surface tension of mercury at that temperature is 0.465 Nm–1. Find excess pressure inside the drop and the total pressure inside the drop. The atmospheric pressure is .

Solution

Correct option is

 

Let T be the surface tension of mercury and R the radius of the drop. Then, the excess pressure inside the drop is

        

           

           = 310 Nm–2 (or Pa). 

The atmospheric pressure is . Therefore, the total inside the drop is

             

                   .

Since the quantities are given upto three significant figures, the total pressure should be written as .

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